1. Field of the Invention
Embodiments of the present invention generally relate to a clamshell and small volume chamber with a fixed substrate support.
2. Description of the Related Art
Reliably producing sub-micron and smaller features is one of the key technologies for the next generation of very large scale integration (VLSI) and ultra large scale integration (ULSI) of semiconductor devices. However, as the fringes of circuit technology are pressed, the shrinking dimensions of interconnects in VLSI and ULSI technology have placed additional demands on the processing capabilities. The multilevel interconnects that lie at the heart of this technology require precise processing of high aspect ratio features, such as vias and other interconnects. Reliable formation of these interconnects is very important to VLSI and ULSI success and to the continued effort to increase circuit density and quality of individual substrates.
As circuit densities increase, the widths of vias, contacts, and other features, as well as the dielectric materials between them, decrease to sub-micron dimensions (e.g., less than 0.20 micrometers or less), whereas the thickness of the dielectric layers remains substantially constant, with the result that the aspect ratios for the features, i.e., their height divided by width, increase. Many traditional deposition processes have difficulty filling sub-micron structures where the aspect ratio exceeds 4:1. Therefore, there is a great amount of ongoing effort being directed at the formation of substantially void-free and seam-free sub-micron features having high aspect ratios.
FIG. 1 is a schematic cross-sectional view of a prior art processing chamber 100 defining a processing region 150. An opening 112 in the chamber 100 provides access for a robot (not shown) to deliver and retrieve substrates 122 from the chamber 100. A substrate support 124 supports the substrate 122 on a substrate receiving surface 126 in the chamber 100. The substrate support 124 is mounted to a lift motor 130 to raise and lower the substrate support 124. In one aspect, the lift motor 130 lowers the substrate support 124 to a substrate transferring position in which the substrate receiving surface 126 is below the opening 112 so that substrates 122 may be transferred to or from the substrate support 124. In another aspect, the lift motor 130 raises the substrate support 124 to a deposition position in which the substrate 122 is in close proximity to a showerhead 140. The showerhead 140 has a central gas inlet 144 for the injection of gases and has a plurality of holes 142 to accommodate the flow of gases therethrough to the substrate 122 disposed on the substrate support 124.
One problem with the use of chamber 100 is aligning the substrate support 124 within the chamber 100. The substrate support 124 may require removal so that the area under the substrate support 124 can be cleaned during routine maintenance. Reinstallation of the substrate support 124 requires aligning the substrate support 124 within the chamber 100. Misalignment of the substrate support 124 may cause non-uniformity of processes performed in the chamber.
Thus, there is a need for an improved processing chamber useful for deposition processes such as atomic layer deposition and cyclical layer deposition.